Strike Delay Likely to Expose Syria Rebels to Attack

Fighters Were Massing in Anticipation of U.S. Attack

WASHINGTON—President Barack Obama's decision to seek congressional authorization is likely to delay any military strike against Syria by weeks, with possible repercussions for U.S. targets, for Syrian forces and for rebels.

However, U.S. defense officials said Saturday that they will be ready to go whenever a presidential order is given.

Defense experts struggled to find a precedent for a sudden pullback from a publicly...